When do you see the placenta on the ultrasound? When is it suppose to form? I had my last scan last Monday (two days shy of 11 weeks) and the yolk sac was still there. Baby’s heartbeat was good, moving around, and they said everything looks good(Thank God!) but I read the placenta is formed by 12 weeks and most women have that line on the belly by 12 weeks, and I don’t have it, and as of a little over a week ago there was still a yolk sac. I had anxiety before pregnancy so it’s just a million times worse the last few weeks!